WASHINGTON -- Mitt Romney's presidential campaign released a television ad Tuesday bashing President Barack Obama for implementing a welfare policy that Romney supported when he was governor of Massachusetts.

"In 1996, President Clinton and a bipartisan Congress helped end welfare as we know it," the ad's voiceover says. "But on July 12th, President Obama quietly announced a plan to gut welfare reform by dropping work requirements."

Welfare, formally known as the Temporary Assistance for Needy Families program, is administered by states within federal rules. Last month, the Department of Health and Human Services invited states to apply for waivers from some rules in order to run "demonstration projects" so that states could "consider new, more effective ways to meet the goals of TANF, particularly helping parents successfully prepare for, find, and retain employment."

Romney's ad doesn't mention that Republican states sought the waiver policy. In a release defending its waiver request from conservative backlash last month, the office of Utah Gov. Gary Herbert (R) said, "Utah's request for a waiver stems from a desire for increased customization of the program to maximize employment among Utah’s welfare recipients."

"Increased waiver authority, allowable work activities, availability of partial work credit, and the ability to coordinate state programs are all important aspects of moving recipients from welfare to work," the governors wrote.

A key difference between 2005 and today is that Republican governors were lobbying Congress to make the change -- they weren't asking the Bush administration to unilaterally invite states to apply for waivers. But the Romney campaign of today is only talking about the policy itself.

"Under Obama’s plan, you wouldn’t have to work and wouldn’t have to train for a job," the ad concludes. "They just send you your welfare check."

In a conference call with reporters, the Romney campaign said the Obama campaign is "throwing up smoke" by pointing to the 2005 letter.

“That letter was commenting on a Senate reauthorization of the welfare program that was pending at the time," said Jonathan Burks, deputy policy director for the Romney campaign. "The senate bill actually increased work participation rates from 50 percent participation rates to 70 percent participation rates and provided increased flexibility in other areas for states in how they administer their TANF program. But it did not provide waivers of the core work requirements and the governors were not requesting waivers for core work requirements."

The 2005 bill, which did not become law, would have allowed HHS to waive "any requirement applicable to the program" for states that wanted flexibility to pursue demonstration projects. Health and Human Services Secretary Kathleen Sebelius has said that "[c]ertain elements of the proposal ... were very far-reaching and would not have been approved under the Department's proposed waivers."

The Obama campaign said Tuesday that as governor, Romney supported waivers far more liberal than those the Obama administration will allow.

"Some of the ideas advocated by Gov. Romney in 2005 undercut the central idea of welfare reform and not all of them would not be approved under the president’s plan,” Obama campaign policy director James Kvaal said on a conference call.

"As governor of Massachusetts, Mitt Romney created a program that gave free cars to state’s welfare recipients and paid for the cost of their insurance, inspections, accidents, titles, registration, repairs, even their AAA membership," Kvaal said.

John Podesta, an Obama advisor who served as chief of staff in the Clinton White House, said the president who ended welfare as we know it does not think Obama has ended welfare reform as we know it.

"I think the Obama administration is trying to administer this program in a way -- in tougher economic conditions, in fact -- in a way that’s trying to accomplish [Clinton’s] goal, which is to give people the dignity of a job," Podesta said. "In advance of this call I did have the opportunity to the extent that matters to check in with the President, and he completely agrees with my analysis of this."

This story has been updated to include comments from Obama and Romney campaign conference calls.